[Serusers] find_export: <append_hf> not found

Hi Lucas,
Would mind sending your ser.cfg file, i am facing the same problems with NAT traversal
I have already read > <http://www.informatik.uni-bremen.de/~prelle/terena/cookbook/Co> okbook_D2/
but it still does not working

This is my ser.cfg file:
#
# $Id: ser.cfg,v 1.21.4.1 2003/11/10 15:35:15 andrei Exp $
#
# simple quick-start config script
#

# ----------- global configuration parameters ------------------------

#debug=3 # debug level (cmd line: -dddddddddd)
#fork=yes
#log_stderror=no # (cmd line: -E)

/* Uncomment these lines to enter debugging mode
debug=7
fork=no
log_stderror=yes
*/

check_via=no    # (cmd. line: -v)
dns=no           # (cmd. line: -r)
rev_dns=no      # (cmd. line: -R)
#port=5060
#children=4
fifo="/tmp/ser_fifo"

# ------------------ module loading ----------------------------------

loadmodule "/usr/local/lib/ser/modules/nathelper.so"

# Uncomment this if you want to use SQL database
loadmodule "/usr/lib/ser/modules/mysql.so"

loadmodule "/usr/lib/ser/modules/sl.so"
loadmodule "/usr/lib/ser/modules/tm.so"
loadmodule "/usr/lib/ser/modules/rr.so"
loadmodule "/usr/lib/ser/modules/maxfwd.so"
loadmodule "/usr/lib/ser/modules/usrloc.so"
loadmodule "/usr/lib/ser/modules/registrar.so"

loadmodule "/usr/lib/ser/modules/textops.so"

# Uncomment this if you want digest authentication
# mysql.so must be loaded !
loadmodule "/usr/lib/ser/modules/auth.so"
loadmodule "/usr/lib/ser/modules/auth_db.so"

# ----------------- setting module-specific parameters ---------------

# -- usrloc params --

#modparam("usrloc", "db_mode", 0)

# Uncomment this if you want to use SQL database
# for persistent storage and comment the previous line
modparam("usrloc", "db_mode", 2)

# -- auth params --
# Uncomment if you are using auth module
#
#modparam("auth_db", "calculate_ha1", yes)
#
# If you set "calculate_ha1" parameter to yes (which true in this config),
# uncomment also the following parameter)
#
#modparam("auth_db", "password_column", "password")

# -- rr params --

# add value to ;lr param to make some broken UAs happy
modparam("rr", "enable_full_lr", 1)

# We will you flag 6 to mark NATed contacts
modparam("registrar", "nat_flag", 6)

# Enable NAT pinging
modparam("nathelper", "natping_interval", 60)

# Ping only contacts that are known to be
# behind NAT
modparam("nathelper", "ping_nated_only", 1)

# ------------------------- request routing logic -------------------

# main routing logic

route{

        # initial sanity checks -- messages with
        # max_forwards==0, or excessively long requests
        if (!mf_process_maxfwd_header("10")) {
                sl_send_reply("483","Too Many Hops");
                break;
        };
        if ( msg:len > max_len ) {
                sl_send_reply("513", "Message too big");
                break;
        };

# special handling for NATed clients; first, nat test is
# executed: it looks for via!=received and RFC1918 addresses
# in Contact (may fail if line-folding used); also,
# the received test should, if complete, should check all
# vias for presence of received
if (nat_uac_test("3")) {
    # allow RR-ed requests, as these may indicate that
    # a NAT-enabled proxy takes care of it; unless it is
    # a REGISTER

if (method == "REGISTER" || ! search("^Record-Route:")) {
log("LOG: Someone trying to register from private IP, rewriting\n");

        # This will work only for user agents that support symmetric
        # communication. We tested quite many of them and majority is
        # smart smart enough to be symmetric. In some phones, like
        # it takes a configuration option. With Cisco 7960, it is
        # called NAT_Enable=Yes, with kphone it is called
        # "symmetric media" and "symmetric signaling". (The latter
        # not part of public released yet.)

        fix_nated_contact(); # Rewrite contact with source IP of signalling
        if (method == "INVITE") {
            fix_nated_sdp("1"); # Add direction=active to SDP
        };
        force_rport(); # Add rport parameter to topmost Via
        setflag(6);     # Mark as NATed
    };
};

        # we record-route all messages -- to make sure that
        # subsequent messages will go through our proxy; that's
        # particularly good if upstream and downstream entities
        # use different transport protocol
        record_route();
        # loose-route processing
        if (loose_route()) {
                t_relay();
                break;
        };

        # if the request is for other domain use UsrLoc
        # (in case, it does not work, use the following command
        # with proper names and addresses in it)
        if (uri==myself) {

if (method=="REGISTER") {

# Uncomment this if you want to use digest authentication
                        if (!www_authorize("200.151.192.13", "subscriber")) {
                                www_challenge("200.151.192.13", "0");
                                break;
                        };

                        save("location");
                        break;
                };

                # native SIP destinations are handled using our USRLOC DB
                if (!lookup("location")) {
                        sl_send_reply("404", "Not Found");
                        break;
                };
        };
        # forward to current uri now; use stateful forwarding; that
        # works reliably even if we forward from TCP to UDP
        if (!t_relay()) {
                sl_reply_error();
        };

}

#
# Forcing media relay if necessary
#
route[1] {
    if (uri=~"[@:](192\.168\.|10\.|172\.16)" && !search("^Route:")){
        sl_send_reply("479", "We don't forward to private IP addresses");
        break;
    };
    if (isflagset(6)) {
        force_rtp_proxy();
        t_on_reply("1");
        append_hf("P-Behind-NAT: Yes\r\n");
    };

    if (!t_relay()) {
        sl_reply_error();
        break;
    };
}

onreply_route[1] {
    if (status =~ "(183)|2[0-9][0-9]") {
        fix_nated_contact();
        force_rtp_proxy();
    };
}

Thanks
Paulo